This invention relates to a method of handling containers in a container yard and more particularly to an improved method capable of preventing misoperation when collecting and stacking containers in a container yard and loading and unloading containers into and from container vessels.
Since the development of container transportation, use of the container transportation system is increasing constantly because of its high utility and efficiency. Because of this, the scale of the container yard where containers are collected, delivered, loaded on and unloaded from container ships is becoming larger and more complicated. However, at present the management of the container yard solely relies upon man power. In order to safely conduct receiving, delivering, loading and unloading operations of a large number of containers in a container yard, it is necessary to perform extremely complicated operations including processing of numerous slips, recording and renewal of ledgers, transmission of cargo handling command signals to loading and unloading machines, and preparation of reports regarding confirmation of completion of the cargo operation. With increasing size of the operations, the danger of misoperations is also increasing. These problems are inevitable due to the fact that it is difficult from the standpoint of engineering to automate material handling operations performed with container handling machines, that there is a limit for properly matching information and material flow (flow of containers) in such complicated systems as container yards, and that the activities of the supervisor of the yards, shippers, land and sea transporting companies and shipowners are restricted by traditional customs from the past. However, since the tendency toward enlarging the scale of the container yards is increasing year after year, even if rapid improvement is impossible, it is necessary to at least partially improve the management of the container yard.
In order to provide efficient management for the handling of extremely large number of containers, it is essential to identify correctly the particular numbers or symbols which are encoded arbitrarily by respective shippers, transporting companies and ship companies. Operations in the yard such as collection or stacking, loading, transshipment and delivery of the containers, should be performed only when such identification is correctly made. However, such individual numbers or symbols are arbitrarily selected by the owners of the container or shippers so that smooth cargo operation can not be assured unless a separate watchman is employed for reading such numbers or symbols, which is of course uneconomical. As the flow of the material (containers) increases, improvement in the turnover rate of the containers is of course advantageous for the efficient management of the yard. However such improvement can be accomplished only by increasing the number of operations thereby increasing, the possibility for misidentification of a container number causes troubles.